This invention is an improvement of a produce of weight-scale sold by Pelouze Scale Co., Evanston, IL. The Pelouze's scale is small balance-type scale. Because it is of the balance-type, its accuracy is far better than other scales of the spring-type, especially under light load, such as letter mails. Although scales of the balance-type usually require a trial and error leveling or balancing operation and thus are less convenient to use than those of the spring-type, the Pelouze's scale does not require such cumbersome leveling operation. The Pelouze's scale employs rotational balancing by the gravitational force involving vertical rotation of the body of the scale. A balance is obtained between an object to weigh at one side and the body of the scale at the other side. In this way, the weight of the object is represented by the angle by which the object makes the body of the scale rotate.
Although the Pelouze's scale is practical and useful, a few inconveniences have been identified.
First, the pointer, by which reading of weight is made on a legend, tends to oscillate for a relatively long period of time. Such oscillation impedes prompt reading of weight.
Second, there is no provision made for adjusting the zero-position of the pointer. Therefore, a straightforward reading may include the zero-position error.
Third, the scale is capable of weighing only up to four ounces (approximately 80 grams). This limitation exists mainly because the scale uses only approximately 90 degrees of rotational angle of the scale body for measurement. Apparently, the scale would be able to double the measurable weight with the same rotational angle if the weight of the scale itself is doubled. However, a problem of this approach is that the rotational angle being the same and the maximum measurable weight being doubled, the accuracy of reading becomes sacrificed to a half.
This invention overcomes these problems.